Is the Atlasian-Canadian common market storyline and the reaction of Canadian political parties meant to be fictional or based on probable reality ?
If it's founded on reality I think the Conservatives would be for it and the other two would be against. They would say harper wants Canada to be just like Atlasia.
In the 1988 election which had the Canada-USA free trade deal as an issue, the Liberals and NDP ran against the deal supported by the progressive-conservative.
http://www.youtube.com/watch?v=jKQPw9vmG04